Atomic & Nuclear Physics (AS91172) is a 3-credit internal. It covers what atoms and nuclei are made of, why some nuclei are unstable, the radiation unstable nuclei give off, and how that radiation decays over time.
The standard splits into three parts:
- Atomic structure and radiation — what protons, neutrons and electrons are, how nuclide notation works, and the properties of alpha, beta and gamma radiation.
- Nuclear equations and half-life — writing balanced decay equations, and using half-life to predict how much of a radioactive sample remains after a given time.
- Uses, hazards and background radiation — where radioactivity is used, and how to stay safe around it.
Two things to know before you start:
- This standard does not cover special relativity, atomic energy levels, or the energy released in fission/fusion — those belong to Level 3 Modern Physics.
- Every formula is on the resource sheet. The marks are for choosing the right relationship, substituting correctly, and explaining the physics in words.
Bring an approved calculator — half-life calculations often involve several repeated halvings.